1. Field of the Invention
The present invention relates generally to transportable conveyor systems, and more particularly, to telescopic transportable conveyor systems.
2. Description of the Related Art
Conveyor systems such as telescopic conveyor systems are commonly used to transport materials from one location to another. There are several known examples of conveyor systems, particularly extendable or telescopic systems, as disclosed, for example, in Canadian patent 2,223,202, Thor Global Enterprises Ltd., issued Jun. 22, 2004, as well as e.g. U.S. Pat. No. 3,378,125 issued Apr. 16, 1968 to Fogg, U.S. Pat. No. 3,825,107 issued Jul. 23, 1974 to Cary et al., and U.S. Pat. No. 5,351,809 issued Oct. 4, 2994 to Gilmore et al.
Telescopic conveyor systems find application in different industries such as the aggregate industry where mobile conveyors are used to form stockpiles of aggregate materials. Depending on the type of industry, the telescopic conveyors will vary in size—for example, those used in the aggregate industry have generally large belts to permit movement of large volumes of aggregates.
Today, the length of the conveyor system is such that they can range from e.g. 40 feet to 80 feet or more for a single conveyor system; for telescopic versions, such conveyor systems are manufactured to have an extended length of e.g. 100 feet to 150 feet or more.
As disclosed in Canadian '202, telescopic conveyor systems utilize technology where one length of the conveyor system is positioned within a second length for transport purposes; when a first length is extended from the second length of conveyor system, the whole system is braced by suitable braces connected to a transport frame. For transport, conveyor systems are generally provided with transport wheels and towed or pulled by a truck or similar vehicle from e.g. a site of manufacture to an area of usage.
For telescopic conveyor systems, obviously the length of the sections of the conveyor system have to be minimized for road usage; normally, a set of two or more transport wheels are located on a base frame mounting the telescopic conveyor system.
When placed at the site of use, radial movement of the conveyor system is required and for this purpose, the prior art has proposed that the transport wheels be positioned laterally of the conveyor system (as opposed to the wheels being in transport position for highway use). When positioned for radial movement, the wheels of the conveyor system are supported by suitable framework extending from the conveyor system to hold the wheels in place and when radial movement is required, the conveyor may be readily rotated from a first to second position.
Problems arise when the conveyor system employs more than one set of transport wheels, possibly in combination with separate wheels, which would be mounted to the conveyor system to function solely as wheels permitting lateral or radial movement. To accomplish this, certain prior art arrangements have employed arrangements to deactivate the transport wheels and position the wheels permitting radial movement in an angular relationship to the conveyor system. The problem encountered in such arrangements is that the transport wheels have to be removed from contact with the substrate (e.g. ground) surface. Some complicated arrangements have been proposed to displace the transport wheels or alternatively, to make such wheels function as wheels for radial movement of the conveyor system.